Blueberries are lousy with antioxidants, satiating fiber, potassium, and more, and according to researchers at the University of Michigan, the colorful fruits may also encourage weight loss. In a study of laboratory rats, scientists found that after 90 days the rats who consumed blueberry-enriched powder as 2 percent of their diet had less abdominal fat, lower triglycerides, lower cholesterol, and improved fasting glucose and insulin sensitivity, than the rats who didn’t consume any blueberry-enriched powder.